STAAR 2013
Plant hormones serve as chemical messengers between cells and tissues. Auxin is a plant hormone that causes the cells on the shady side of a plant shoot to elongate. The response enabled by auxin is known as —
F geotropism
G transpiration
H phototropism
J photosynthesis
H phototropism
What is the role of mRNA in expressing specialized structures?
F Making energy available for cellular activities
G Creating bonds to form biomolecules
H Producing sugars that assist with replication
J Providing information to form proteins
J Providing information to form proteins
A science class is planning a field trip to a local farm that has a large pond. Which of the following lists the order of biological organization from smallest to largest that the students can expect to find at the pond?
F Organism, community, population, ecosystem
G Organism, population, community, ecosystem
H Population, organism, community, ecosystem
J Population, organism, ecosystem, community
G Organism, population, community, ecosystem
Scientists around the world use a standardized taxonomic system. Why would scientists want to use a taxonomic system that is standardized?
A In order to avoid confusion with the identification of organisms
B Because Linnaeus established the system
C So that Latin names can be applied for a practical purpose
D In order to place organisms in different groups
A In order to avoid confusion with the identification of organisms
People who have leukemia, a cancer that affects white blood cells, are often given Cytarabine. This drug inhibits the synthesis of DNA. Which phase of the cell cycle is most affected by Cytarabine?
A G1 phase
B S phase
C G2 phase
D M phase
B S phase
Characteristics such as a widow’s peak or attached earlobes are determined by the genetic code. Which components of DNA are referred to as the genetic code?
F Phosphate groups
G Nitrogenous bases
H Deoxyribose sugars
J Hydrogen bonds
G Nitrogenous bases
Sexual reproduction in animals depends on the production of gametes. Which of these processes produces gametes in animals?
F Mitosis
G Fertilization
H Meiosis
J Binary fission
H Meiosis
Which of the following biomolecules typically contains both nitrogen and phosphate?
F Lipid
G Protein
H Nucleic acid
J Carbohydrate
H Nucleic acid
During meiosis, homologous chromosomes exchange genetic material. This exchange of genetic material —
A increases the genetic variation
B reduces the diploid number to the haploid number
C increases the haploid number to the diploid number
D reduces the probability of mutations
A increases the genetic variation
Invasive plant species affect the interactions of living and nonliving components of an ecosystem, so the removal of invasive plants is often necessary. The goal of most plant-control methods is to disrupt or inhibit the function of different plant systems. For example, insects can be used to chew through roots in order to reduce a plant’s ability to absorb water. Which of these functions would be most immediately affected by a reduction in water uptake by roots?
F Disease resistance
G Seed dispersal
H Sunlight absorption
J Photosynthesis
J Photosynthesis
Which cellular process takes place in the ribosomes that are bound to the endoplasmic reticulum?
A The breakdown of waste material
B The conversion of radiant energy to glucose
C The synthesis of new proteins
D The replication of nucleic acids
C The synthesis of new proteins
Carbohydrates are more easily metabolized than lipids. However, on a gram-for-gram basis lipids provide cells with more —
F nitrogen
G proteins
H structure
J energy
J energy
The cellular process known as the sodium-potassium pump was discovered in the 1950s by Jens Christian Skou, a Danish scientist. This process is a form of active transport that moves three sodium ions to the outside of a cell for every two potassium ions that it moves into the cell. Which of these best explains why energy is needed for active transport?
A Ions are negatively charged.
B Ions are attached to large proteins.
C Ions are trapped inside the plasma membrane.
D Ions are moved against the concentration gradient
D Ions are moved against the concentration gradient
Scientists studying illnesses caused by chemically contaminated food conduct research to minimize the effects of these diseases on society. These chemicals harm the body through interactions between the digestive system and the immune system. Scientists conducting this research are likely to describe which of these interactions between the digestive and immune systems?
F Chemicals enter the immune system through a break in the skin. The chemical contamination is then passed to the digestive system by the circulatory system.
G The immune system transforms the chemicals in the contaminated foods into harmless chemicals. These harmless chemicals are then broken down by the digestive system.
H When contaminated foods are eaten, the immune system prevents the chemicals from entering the digestive system.
J Chemicals enter the digestive system through contaminated foods. Once in the body, the chemical contaminants impair the body’s ability to fight off infectious diseases.
J Chemicals enter the digestive system through contaminated foods. Once in the body, the chemical contaminants impair the body’s ability to fight off infectious diseases.
What two human systems work together to provide body cells with a constant supply of oxygen while removing carbon dioxide waste products?
A Nervous and endocrine
B Muscular and skeletal
C Respiratory and circulatory
D Excretory and Respiratory
D Excretory and Respiratory
Arthropods are joint-legged animals. Spiders, crabs, pill bugs, centipedes, and millipedes are examples of the many types of arthropods. Which of these arthropods are most closely related?
F Arthropods of the same family
G Arthropods of the same class
H Arthropods of the same genus
J Arthropods of the same species
J Arthropods of the same species
Atherosclerosis is a disease that obstructs blood flow and, therefore, oxygen supply to target organs. A major component of atherosclerosis is the excessive reproduction of smooth muscle cells of the blood vessels. Certain drugs may have the potential to reverse or prevent the unregulated reproduction of the diseased blood-vessel cells. Which of these processes is the most likely target of these drugs?
F Cell division
G Erythroblast differentiation
H DNA transcription
J Cellular respiration
F Cell division
Diatoms are one of the most common types of phytoplankton in marine habitats. Like plants, diatoms contain chlorophyll and produce glucose from which of the following?
A O2 and ATP
B CO2 and O2
C ATP and H2O
D CO2 and H2O
D CO2 and H2O
During the final stages of human gestation, receptors for the hormone oxytocin increase on the smooth muscle cells of the uterus. The release of oxytocin during labor stimulates the smooth muscle tissue in the wall of the uterus. The vigorous contraction of the uterine smooth muscle helps push the baby through the birth canal so that delivery can occur. This process involves the interaction of which organ systems?
A Endocrine and muscular only
B Endocrine and reproductive only
C Endocrine, muscular, and reproductive
D Endocrine, reproductive, and excretory
C Endocrine, muscular, and reproductive
Severe acute respiratory syndrome (SARS) is an illness caused by a coronavirus. Symptoms including a high fever, headaches, and body aches typically occur two to seven days after infection by the virus. SARS is more serious in elderly patients. This information suggests that the reproductive cycle of the SARS virus is —
A lysogenic, because the virus is a coronavirus
B lytic, because the virus causes respiratory illness
C lysogenic, because the virus primarily affects older people
D lytic, because of the quick onset of symptoms after infection
D lytic, because of the quick onset of symptoms after infection
A dog’s pituitary gland produces the hormone ACTH, which stimulates the adrenal glands to secrete cortisol. Cortisol helps regulate body weight, mineral balance, the structure of connective tissue, the production of white blood cells, and skin health. When cortisol levels are low, the pituitary gland secretes ACTH. When cortisol levels are high, the pituitary gland stops secreting ACTH. Based on this information, which of the following would most likely be the cause of elevated levels of cortisol in a dog?
A Undersized adrenal glands
B An excess of ACTH
C An inactive pituitary gland
D An immune response to the excess level of cortisol
B An excess of ACTH
When a person is suddenly cut by a sharp object, a nervous impulse is sent along a sensory neuron to the spinal cord. The impulse is immediately transmitted through motor neurons to produce a response. Which of the following correctly identifies and describes this response?
F It is a conditioned response that occurs only to prevent injury.
G It is a learned response that does not occur in infants and small children.
H It is a reflex response that causes various muscles to contract in order to move away from the object.
J It is a voluntary response that is initiated only after the impulse has been carried to the relevant area in the brain.
H It is a reflex response that causes various muscles to contract in order to move away from the object.
Scientists can bioengineer skin in a laboratory to treat severe burns and other types of skin injuries. This bioengineered tissue is grown from living cells. The cellular process that enables the cells to grow and develop into tissue is —
F conjugation
G meiosis
H budding
J mitosis
J mitosis
In the 1880s, Louis Pasteur developed a method of weakening viruses. The weakened viruses could be injected into healthy individuals.
How is this method effective in fighting viral diseases?
A The immune system develops antibodies in response to the weakened viruses.
B The weakened viruses attach to unaffected viruses in the host and interrupt the viral reproductive cycle.
C The rate of genetic mutation in the host is decreased due to the introduction of weakened viruses.
D Weakened viruses are unable to enter the host organism.
A The immune system develops antibodies in response to the weakened viruses.
Telophase is a stage of a cellular process that begins after the chromosomes have moved to opposite poles of the cell. During which cellular process does telophase occur?
A Translation
B Interphase
C Transcription
D Mitosis
D Mitosis